Max velocity for soft 45/70 boolits?

[Nardoo]

How fast can I drive a 400 odd grain 20/1 lead/tin gas check boolit in my 45/70 before I run in to leading problems and accuracy loss?

My WW plus 2% Sn boolits are fine to almost 2000 fps but I am not getting enough terminal expansion for hunting.

Thanks
Nardoo

[JSH]

That is kind of a loaded queation, so to speak.
A lot of variables to look at. Each bore has it's own preferences, likes and dislikes as to when it gives up it's all. You could then change alloy and maybe go faster yet?
As to terminal performance and wanting expansion, it is a 45 what kind of expansion is needed. You might also do a search on the soft nose CB's. Yes they are a pita, but just use them for hunting and your other alloy for practice
My 45-70 is running right at 1250-1300 neighborhood, with a 500 PB. I feel no need to go any faster, nor a whole any larger. BTW this is out of a pisola, I can't stand much more than that.
Jeff

[45 2.1]

This depends on how you are loading and useing the boolit. For hunting, I use paper patched boolits which don't have any real limitations and really expand and hold together. Try yours and find out.

[44man]

You don't have to drive a soft boolit fast for it to work, load for the best accuracy. A big, soft, round nose at 1200 fps is deadly. For harder boolits the nose shape is more important and a round or pointy nose is no good. You need a big, flat meplet.
I can't count the deer I have killed with a .45 round ball from flinters and my cap and ball even puts them down fast. Last one I shot with the cap and ball Ruger Old Army made one leap and hit the ground flat.
Your boolit design is more important then speed. Shooting the wrong boolit fast only makes a small hole appear faster. Small holes don't kill fast and you can lose deer or whatever you are hunting.

[Ricochet]

I started off loading my Marlin to the top levels from the loading manuals and turned my shoulder a rainbow of pretty colors with that nasty hard curved buttplate for many years. Finally accepted that the .45-70 started off as a blackpowder cartridge. It worked fine with blackpowder loads, and it works fine at blackpowder velocity levels. My favorite load now is with the Lyman #457122HP Gould boolit in the 1500 FPS range. Much easier to shoot, and certainly plenty for deer-class game.

[Bass Ackward]

Nardoo,

Saying how fast you can go is pretty open. Bigger bores can be way different. Especially if you need to use softer lead where some leading is likely to take place.

I will tell you this. I can go faster and shoot more accurately longer with 20-1 than I can with ACWW. That is still leading.

This board tends to treat all leading as a dirty word. And you can work to avoid it totally. Sometimes that can be foolish. In truth, some of my most accurate loads will lead even in my smoothest barrels. (handguns and 22LRs mostly) Especially in the heat of summer. It's a sign that you aren't over lubed. :grin: In fact some loads don't really shine until you get leaded up.

I have a T-bolt that will just eat a hole with almost any brand of 22 ammo at 50 yards and if you run a brush through it right after firing that group, it will look like it is snowing. Then it takes quite a few rounds to get that accuracy level back.

All leading will eventually build up to the point accuracy will be lost. The key for me is that it doesn't build up within a reasonable amount of shooting for that caliber. Like thousands of rounds for 22LRs. Hundreds for handguns.

20-1 does that much better than ACWW for handguns and bigger bores. I should say that from my experience, any mix that doesn't contain antimony will have accuracy last longer unless you can add enough antimony or harden it by HTing to stop it all together. 20-1 is just the mix I use most because it is easy to make repeatable without using too much tin. (my lead is free so I don't mind paying for tin)

I usually have more problems from having to clean because of lube than I do from having to clean because of lead. So pick what mix you want, load to minimize leading of coarse, but if you need velocity for softer lead for what you are doing, shoot it and see what happens.

[Bass Ackward]

I guess that was important enough that I just had to say it twice.

[Larry Gibson]

I push a Lee 457-500-GC bullet cast of 1-16 alloy right at 1800 fps with sub 2 MOA 4 shot (magazine capacity) groups at 100 yards with the 1st group out of the clean barrel. The 2d group runs 2-3 MOA and subsequent groups will stay in the 3-4 moa range. About at shots 5-6 I start noticing lead washing at the muzzle end of the barrel. Since this is a hunting load I don't expect to shoot more than the first 4 shots before cleaning again anyway. Five or six strokes with Shooter's Choice (I use GM Top Engine Cleaner in lieu of) on a bronze brush keeps the lead out (pun intended). I have driven this bullet up to 2050 fps with pretty much the same results but in the 8 1/2 lb rifle it gets pretty uncomfortable real quick. The 1800 fps load is quite deadly at the ranges I use this cartridge/rifle. I've shot 2 elk with the 500 gr/1800 fps load and both gave complete penetration and obvious expansion. I did recover a 458483 (400 gr GC RN bullet) cast of the 1-16 alloy at the same 1800 fps that I dispatched an injured elk with. I shot him (a spike) at about 50 yards (slight upward angle) with the bullet entering the neck and traveling through all the neck vetibrae, down along under the back bone and lodging in the hind quarter. That's a lot of penatration. The bullet lost the Hornady GC (is that "bullet failure"? LOLs!) yet still weighs 340 gr for 85% weight retention.

Larry Gibson

[Nardoo]

Thanks for the great advice guys. I realise that lower velocities are usually fine but I have a special hunting case where I need lots of velocity and bullet weight in a light, handy rifle. I use a .338 and a .375 HH a lot but the longer I carry them the longer my arms get.
I love using those black powder level loads in the 45/70 and do so most of the time but I have a hankering to hunt sambar with cast boolits this year so need to develop the velocity.
And those soft points that I would love to try just don't work out in my beagled mold. I guess I need to start looking for a large mepletted .461" gas check mold. These things are not that common here. There are a couple of potential group buys being talked about which sound great.
Now, for a weeks holiday on the coast. Bye!

[Buckshot]

..............Paul Matthews reported 1800+ fps from his Marlin M95 with MG rifling and a pure lead slug. A pure lead paper patched 405gr from my MkIV Martini @ 1250 fps looked like a ping pong ball with a hole in it after firing into the dirt berm at 50 yards. The slug flowed backwards from the nose and you could look in the back and see the base :-)

................Buckshot

[dubber123]

I think maybe the lube has as much to do with it? It may be different, but my short 20" barrelled .54 BP carbine shoots a 450 gr. plains bullet at 1,450fps. cast of pure lead into an inch at 50 yds., no leading I can see. LOTS of bore butter on the bullet though. I still scratch my head when I sometimes get lead at 1,200fps. in revolvers. Confusing I guess.

[pdawg_shooter]

I get 2218 fps out of my .458mag using a 20 to 1 mix. Just size to .4515 and give them two wraps of 16lb typing paper. They go 1906 in my 45.70 and make a fine deer load. Drops them quick !

[drinks]

Larry;
Whatinell is a 547-50-GC?. The world wonders!

[Larry Gibson]

Larry;
Whatinell is a 547-50-GC?. The world wonders!

Beats the heck out of me...apparently this computor can't type what I want it to! Thanks for pointing that gross error out, I fixed it.

Larry Gibson

[Ricochet]

Whatinell is a 547-50-GC?. The world wonders!
A boolit of rather low sectional density.